Heating installation and method for controlling the heating installation

ABSTRACT

A heating installation includes a heat pump, heating fluid piping passing through a condenser of the heat pump to exchange heat between refrigerant and heating fluid, first and second objects heated by the heating fluid to first and second set temperatures, a valve switchable between first and second positions to supply heating fluid to the first and second objects, sensors detecting first and second actual temperatures at the first and second objects, and a control. The heat pump also has an evaporator, a compressor and an expansion device. The control in a demand dependent mode, is configured to determine a first demand based on the first set and actual temperatures and a second demand based on the second set and actual temperatures, and is configured to switch the valve to the first and second positions based on comparison of the first and second demands. A method for controlling a heating installation heats the first or second object based on such a comparison.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. National stage application claims priority under 35 U.S.C.§119(a) to European Patent Application No. 08005301.0, filed in Europeon Mar. 20, 2008, the entire contents of which are hereby incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates to a heating installation and a method forcontrolling the heating installation. It is, however, to be understoodthat the present invention may also be incorporated in combined heatingand cooling installations and is then implemented for controlling theinstallation in the heating mode. More particularly, the presentinvention relates to a heating installation comprising a heat pump,particularly an air-source heat pump, having an outdoor evaporator, acompressor, a condenser and an expansion means connected by arefrigerant piping in a cycle; a heating fluid piping passing throughthe condenser for exchanging a heat between the refrigerant and theheating fluid and at least a first and a second object to be heated bythe heating fluid to a first set temperature and a second settemperature.

BACKGROUND ART

In existing systems such a heating installation is controlled based on aset priority. That is, a user manually inputs which of the first andsecond object is to be served first, if both the first and the secondobject have a heat demand, i.e. require supply of heating fluid. Henceand independently from the amount of heat which is demanded by thepriority object, the priority object is served, whereas the other objectis set on hold until the demand of the priority object has beenstatisfled.

In case the priority is set to the domestic hot water production, thereis a possibility that the indoor temperature is dropping below the levelof comfort. In case the priority is set to the space room heating, theremay occur discomfort in the domestic hot water production if aninsufficient hot water production takes place.

SUMMARY

Hence, it is the object of the present invention to provide a heatinginstallation and a method for controlling a heating installation asdescribed in the introductory part which enables both to prevent severetemperature drops in e.g. rooms to be heated and provide sufficientheating to e.g. hot water in a hot water container at the same timebeing as efficient as possible.

This object is solved by a heating installation as defined in claim 1and a method for controlling the heating installation as defined inclaim 9.

Aspects of the present invention are named in the dependent claims.

The principle idea of the present invention is to provide the heatinginstallation with an adaptive control which controls the supply ofheating fluid to a first and second object to be heated based on acomparison of the heating demand of the first and second object. Hence,the present invention considers both heating demands of the objects tobe heated compares the demands and based on the comparison decides whichof the first and second object is to be served first, i.e. supplied withheating fluid.

The heating installation of the present invention comprises a heat pumphaving an evaporator, a compressor, a condenser and a expansion meansconnected by a refrigerant piping in a cycle. It is to be understoodthat the heat pump in a combined heating and cooling installation mayalso be operated in a cooling mode, that is reversed compared to theheating mode. In the cooling mode, the evaporator will then serve thecondenser and the condenser will serve as the evaporator of the heatpump. Furthermore, the heating installation of the present inventioncomprises a heating fluid piping passing through the condenser forexchanging heat between the refrigerant and the heating fluid as well asat least a first and a second object to be heated by the heating fluidto a fist set temperature and a second set temperature, respectively. Inaddition, in order to selectively supply heating fluid to heat the firstobject or the second object, the heating installation of the presentinvention comprises a valve which is at least switchable between a firstposition for supplying heating fluid to heat the first object and asecond position for supplying heating fluid to heat the second object.In addition, at least two sensors are provided for detecting the firstand the second actual temperature at the first and the second object,respectively. The control of the heating installation of the presentinvention is configured to, in a demand dependent mode, determine afirst demand based on at least the first set temperature and the firstactual temperature and a second demand based on at least the second settemperature and the second actual temperature and based on the first andsecond demand switches the valve to the first and the second position toeither serve the first object or the second object, hence, satisfyingthe first or the second demand (heating demand). It is to be understoodthat the first demand is determined based on at least the first settemperature and the first actual temperature but other parameters mayalso be considered in determining the demands, such as time andtemperature concurrent. If these parameters other than the saidtemperatures are sufficiently significant, the demand may also bedetermined based on these parameters only. Further, the first demand andthe second demand may be determined based on at least the differencebetween the set temperature and the actual temperature.

In a preferred embodiment, the control is configured to switch the valveto the first position if the first demand is higher than the seconddemand and to switch the valve to the second position if the seconddemand is higher than the first demand. Self-evident the control isconfigured to switch the valve to the first position, if there is nosecond demand and to switch the valve into the second position, if thereis no first demand. Nevertheless, even if there are a first demand and asecond demand and according to this preferred embodiment, the controlswitches the valve so as to serve the higher demand.

As previously indicated, it is considered preferred that the firstobject is at least one heat emitter which is arranged in a room to beheated, wherein the heat emitter on an upstream side thereof isconnected to the heating fluid piping via said valve. According to onepreferred embodiment, the heat emitter comprises a floor heating loopsor may entirely consist of a floor heating loops. However, also acombination of radiators and floor heating loops may form the heatemitter of the present invention.

In this embodiment it is preferred that the first actual temperature isthe actual flow temperature to the heat emitter, i.e. the flowtemperature of the heating fluid to the heat emitter and the first settemperature is the desired flow temperature to the heat emitter, whichmay be required to obtain the desired room temperature.

Moreover and as also previously indicated, the second object is watercontained in a hot water container. According to one embodiment aportion of a pipe, the upstream side of which being connected to theheating fluid piping via said valve, is connected to a heat exchangerfor transferring the heat from the heating fluid to the water. Accordingto another embodiment, the portion of the pipe forms the heat exchangerand passes, e.g. in form of a coil, through the interior of the hotwater container, thereby transferring the heat from the heating fluid tothe water.

In this embodiment, it is preferred that the second actual temperatureis the actual water temperature of the water contained in the hot watercontainer and to be heated and the second set temperature is the desiredtemperature of said water.

Further and to in order to enable the user to select between thepreferred demand dependent mode and a priority mode the control has aninput device for selecting the mode, wherein in the priority mode apriority is manually set with respect to the first or the second object.The input device may also comprise an input element, such as a bottom,for selecting a boosting mode, in which an additional heater in the hotwater container is manually activated to quickly heat up the water inthe container if required.

Furthermore and as previously mentioned, the present invention alsoprovides a method for controlling a heating installation as describedabove. The control method comprises the steps of calculating a firstdemand based on at least the first set temperature and the first actualtemperature and a second demand based on at least the second settemperature and the second actual temperature, comparing the first andsecond demand and heating either the first object or the second objectbased on the comparison, that is to either supply heating fluid to thefirst, object or to the second object.

The embodiments of the method of the present invention correspond to thepreferred embodiments of the heating installation described above sothat in order to avoid repetitions reference is made to the dependentclaims and the above description only.

BRIEF DESCRIPTION OF DRAWINGS

Additional features and advantages of the present invention will becomeapparent from the detailed description of a preferred embodiment withreference to the accompanying drawings in which:

FIG. 1 is a perspective view of a room heating and cooling installationin which the present invention may be implemented;

FIG. 2 is a system diagram for schematically explaining the componentsof the installation shown in FIG. 1;

DETAILED DESCRIPTION OF EMBODIMENT(S)

The present application will be described in the following as beingimplemented in an installation which is capable of heating and cooling apredetermined space (room) and heating water in a hot water container,the water via piping 50 being used for sanitary purposes like the tabs52, the shower 51, etc. (see FIG. 1). Yet it is to be understood thatthe present invention may also be implemented in other installation thanthe one shown in FIGS. 1 and 2, where appropriate.

The installation shown in FIG. 1 consists of three major components, anoutdoor unit 10, an indoor unit 20 and a hot water container 30. Theoutdoor unit 10 is connected to a piping 11, 12 which connects theoutdoor unit 10 to the indoor unit 20. The outdoor unit 10 comprises aninlet/outlet 12 and an outlet/inlet 11 for a refrigerant piping. Theindoor unit 20 comprises an inlet/outlet 24 and an outlet/inlet 23 forthe refrigerant piping. In addition, the indoor unit has an outlet 21and an inlet 22 for the fluid to be circulated in the fluid circuit(depending on the mode the fluid is heating or cooling fluid). The fluidmay be water or a brine solution. The piping downstream of the outlet 21is connected via a valve 32 to a piping 31 and a piping 35. The piping31 passes through the interior of the hot water container 30 in form ofa coil (see FIG. 1) and leaves the hot water container 30 via a piping34 connected to a piping 36 leading to the inlet 22. The piping 35downstream of the valve 32 leads to a heat emitter 41 and/or underfloorheating loops 40 and then is refed to the indoor unit via the piping 36and the inlet 22.

As will be appreciated, the connections 11, 12 to the outdoor unit 10and the connections 23, 24 to the indoor unit may respectively bereversed depending on the mode in which the system is operated, i.e. theheating mode or the cooling mode.

As shown in FIG. 2 the outdoor unit comprises an evaporator and/orcondenser 14, a four-way valve 16, a compressor 15 and an expansiondevice 13, which is may be an electric valve or a capillary. The indoorunit 20 inter alia comprises a condenser/evaporator 25. These componentsform a heat pump. Hence, the evaporator/condenser 14, the compressor 15,the condenser/evaporator 25 and the expansion device (means) 13 areconnected in this order in a cycle or loop by means of a refrigerantpiping 17, 18. A refrigerant is circulated by means of the compressor 15in the refrigerant piping 17, 18. In the heating mode the refrigerantcirculates clockwise in FIG. 2. Hence, the refrigerant leaving thecondenser 25 and having a first temperature Ti upstream of the expansiondevice (means) 13 passes the expansion device (means) 13, the pressurebeing reduced. Afterwards, the refrigerant passes the evaporator 14 andis evaporated having a second temperature T2 downstream of theevaporator 14 higher than the first temperature. After leaving theevaporator 14, the refrigerant passes through the compressor, thepressure being increased. Finally, the refrigerant is again condensed tothe first temperature Ti in the condenser 25, wherein the heat from therefrigerant is transferred to the water or brine solution (fluid) in thepiping connected to the indoor unit via the connections (inlet 22 andoutlet 21.

In the cooling mode, this process is reversed, wherein the component 14then serves as condenser and the component 25 as evaporator. Therefrigerant then circulates counter-clockwise in FIG. 2.

The indoor unit 20 further comprises a pump 27 and a backup heater 26.The pump serves for circulating the fluid (heating or cooling fluid) inthe fluid circuit (21, 31, 34, 35, 36, 22). The purpose of the backupheater 26 is to cope with situations in which the heat pump describedabove is not capable to satisfy the entire heating demand (at very lowtemperatures, e.g. below −10 degrees Celsius). This backup heater 26 insome cases may also be omitted.

In the heating mode the fluid (heating fluid) enters the indoor unit 20through the inlet 22, passes the condenser 25, wherein heat istransferred from the refrigerant to the fluid, then flows through thebackup heater 26 in which the fluid may be additionally heated ifnecessary and subsequently passes the pump 27 which circulates the fluidin the fluid circuit. Afterwards and by controlling the valve 32 thefluid is either supplied to the floor heating loops 40 and the heatemitter 41 (see FIG. 1) or alternatively to the hot water containerpiping (31, 34). In the latter case, the fluid may enter the hot watercontainer 30 by means of the piping 31 passing the heating coil insidethe hot water container 30 thereby transferring the heat from the fluidto the water contained in the hot water container 30 and subsequentlybeing reefed to the circuit by the pipings 34 and 36 finally beingreintroduced into the indoor unit via the inlet 22. Similar, the fluidmay also be supplied to the floor heating loops 40 as a heat emitter orthe radiator 41 shown in FIG. 1 and subsequently be reintroduced in tothe indoor unit via the inlet 22. In case the temperature of the fluidis not sufficient to heat the hot water in the hot water container anadditional (booster) heater 33 may be provided in the hot watercontainer.

As previously mentioned, the circulation of the fluid in the coolingmode is the same but the cycle of the heat pump (flow direction of therefrigerant) is reversed.

Moreover, the system comprises a temperature sensor 60 which detects thetemperature of the heating fluid leaving the indoor unit which, in thefollowing, is considered as the actual flow temperature of the heatingfluid. An additional temperature sensor 63 is provided to detect thetemperature of the hot water in the hot water container 30.

In the following, the control of the embodiment of the present inventionis explained.

An input device (not shown) which in general will be arranged in or onthe indoor unit is used to input a desired flow temperature (first settemperature) of the heating fluid to the heat emitters 40, 41 and thedesired water temperature in the hot water container 30 (second settemperature).

Alternatively, the flow temperature may also be adapted automaticallybased on the outdoor temperature (ambient temperature) and/or the roomtemperature in the room to be heated. That is, if the outdoortemperature decreases the flow temperature is increased and vice versaand/or if the low temperature is too high for the room to be heatedresulting in a high cycling rate between supply and nonsupply of heatingfluid to the heat emitter the flow temperature is decreased and viceversa.

In operation, the control via the sensors 60, 63 detects the flowtemperature of the heating fluid leaving the indoor unit

as a first actual temperature and the temperature of the hot water inthe hot water container 30 as a second actual temperature.

Based on the first set and second set temperature and the first andsecond actual temperature the control determines a first demand of theheat emitters 40, 41 and a second demand of the hot water container 30.This calculation or determination may include the difference between thefirst set and the first actual temperature and the difference betweenthe second set and actual temperature. Also other parameters such as mayinfluence the result of the first and the second demand. Theseparameters may be selected from the group of field settings which can beselected by the installer.

If only the heat emitters 40, 41 or the hot water container 30 demandheat, i.e. that the heating fluid is supplied to either the heatemitters 40, 41 or the hot water container 30, this demand is satisfied.If both the heat emitters 40, 41 and the hot water container 30 demandheat, the control compares the first and the second demand and dependingon which demand is higher serves the heat emitters 40, 41 or the hotwater container 30. I.e. if the first demand is higher, the valve 32switches to the first position supplying heating fluid to the heatemitters 40, 41 via the piping 35. In case the second demand is higherthan the first demand, the valve 32 switches to the second positionsupplying heating fluid via the piping 31 to the hot water container 30passing the heating coil inside the hot water container 30 being refedvia the piping 32 and 36 to the indoor unit, whereby the hot water inthe hot water container 30 is heated by transfer of heat from theheating fluid flowing through the heating coil to the water in thecontainer.

If a user selects a priority mode via the input device (not shown) ofthe described heating installation, the control changes from the abovedescribed demand dependent mode to a priority mode, wherein the user hasto set a priority, either for heating the rooms, i.e. supplying heatingfluid to the heat emitters 40, 41 or the hot water in the hot watercontainer 30, i.e. supplying heating fluid to the hot water container30. In addition, the system may comprise a button to select a “boostingmode” which enables to activate the additional heater 33 in the hotwater container 30 to quickly heat up the water in the hot watercontainer to quickly obtain the desired temperature (second settemperature). This additional heater 33 may also be activated by meansof the control in the demand dependent mode if the first demand ishigher than the second demand and the heating fluid is supplied to theheat emitters 40, 41 rather than to the hot water container 30 so as toconcurrently obtain the desired water temperature in the hot watercontainer 30 if the actual temperature measured by the sensor 63 dropsbelow a predetermined value lower than the desired temperature of thehot water in the container (second set temperature).

Although the present invention has been described with respect to acombined heating and cooling installation, the present invention mayalso be applied to a heating installation without the coolingcapability. In addition, the present invention has been described withrespect to heat emitters 40, 41 and a hot water container 30 as firstand second object. It is, however, to be understood that the presentinvention may also be implemented to heat other objects than the abovedescribed.

1. A heating installation comprising: a heat pump having an evaporator,a compressor, a condenser and an expansion device connected by arefrigerant piping in a cycle; a heating fluid piping passing throughthe condenser to exchange heat between a refrigerant and a heatingfluid; a first and second objects arranged to be heated by the heatingfluid to first and second set temperatures, respectively, a valveswitchable between at least a first position in which the heating fluidis supplied to heat the first object and a second position in which theheating fluid is supplied to heat the second object; at least twosensors arranged and configured to detect first and second actualtemperatures at the first and second objects, respectively, and acontrol, in a demand dependent mode, configured to determine a firstdemand based on at least the first set temperature and the first actualtemperature and a second demand based on at least the second settemperature and the second actual temperature, and configured to switchthe valve to the first position and the second position based on acomparison of the first and second demand.
 2. The heating installationas set forth in claim 1, wherein the control is further configured toswitch the valve to the first position if the first demand is higherthan second demand and to switch the valve to the second position if thesecond demand is higher than first demand.
 3. The heating installationas set forth in claim 1, wherein the first object includes at least oneheat emitter arranged in a room to be heated, the heat emitter having anupstream side thereof connected to the heating fluid piping via thevalve.
 4. The heating installation as set forth in claim 3, wherein theheat emitter includes floor heating loops.
 5. The heating installationas set forth in claim 3, wherein the first actual temperature is anactual flow temperature to the heat emitter and the first settemperature is a desired flow temperature to the heat emitter.
 6. Theheating installation as set forth in claim 1, wherein the second objectincludes water contained in a hot water container, and a portion of apipe is connected to a heat exchanger configured and arranged totransfer the heat to the water or forms the heat exchanger passingthrough the interior of the hot water container, the portion of the pipehaving an upstream side connected to the heating fluid piping via thevalve.
 7. The heating installation as set forth in claim 6, wherein thesecond actual temperature is an actual water temperature of the watercontained in the hot water container, and the second set temperature isan desired temperature of the water.
 8. The heating installation as setforth in claim 1, wherein the control has an input device arranged andconfigured to select between the demand dependent mode and a prioritymode in which a priority is manually set with respect to the firstobject or the second object.
 9. A method for controlling a heatinginstallation, which includes: a heat pump having an evaporator, acompressor, a condenser and an expansion device connected by arefrigerant piping in a cycle; a heating fluid piping passing throughthe condenser to exchange heat between a refrigerant and a heatingfluid; first and second objects arranged to be heated by heat of theheating fluid to first and second set temperatures, respectively, themethod comprising: detecting first and second actual temperatures of thefirst and second objects, respectively; calculating a first demand basedon at least the first set temperature and the first actual temperatureand a second demand based on at least the second set temperature and thesecond actual temperature; comparing the first and second demands; andheating either the first object or the second object based on thecomparison.
 10. The method as set forth in claim 9, wherein the firstobject is heated when the first demand is higher than second demand, andthe second object is heated when the second demand is higher than firstdemand.
 11. The method as set forth in claim 9, wherein the first objectincludes a heat emitter arranged in a room to be heated, and the firstactual temperature is an actual flow temperature to the heat emitter inthe room and the first set temperature is a desired flow temperature tothe heat emitter.
 12. The method as set forth in claim 9, wherein thesecond object includes water contained in a hot water container, and thesecond actual temperature is an actual water temperature of the watercontained in the hot water container, and to be heated and the secondset temperature is a desired temperature of the water.
 13. The method asset forth in claim 10, wherein the first object includes a heat emitterarranged in a room to be heated, and the first actual temperature is anactual flow temperature to the heat emitter in the room and the firstset temperature is a desired flow temperature to the heat emitter. 14.The method as set forth in any one of claims 10, wherein the secondobject includes water contained in a hot water container, and the secondactual temperature is an actual water temperature of the water containedin the hot water container, and the second set temperature is a desiredtemperature of the water.
 15. The method as set forth in any one ofclaims 11, wherein the second object includes water contained in a hotwater container, and the second actual temperature is an actual watertemperature of the water contained in the hot water container, and thesecond set temperature is a desired temperature of the water.
 16. Theheating installation as set forth in claim 2, wherein the first objectincludes at least one heat emitter arranged in a room to be heated, theheat emitter having an upstream side thereof connected to the heatingfluid piping via the valve.
 17. The heating installation as set forth inclaim 2, wherein the second object includes water contained in a hotwater container, and a portion of a pipe is connected to a heatexchanger configured and arranged to transfer the heat to the water orforms the heat exchanger passing through the interior of the hot watercontainer, the portion of the pipe having an upstream side connected tothe heating fluid piping via the valve.
 18. The heating installation asset forth in claim 2, wherein the control has an input device arrangedand configured to select between the demand dependent mode and apriority mode in which a priority is manually set with respect to thefirst object or the second object.
 19. The heating installation as setforth in claim 3, wherein the second object includes water contained ina hot water container, and a portion of a pipe is connected to a heatexchanger configured and arranged to transfer the heat to the water orforms the heat exchanger passing through the interior of the hot watercontainer, the portion of the pipe having an upstream side connected tothe heating fluid piping via the valve.
 20. The heating installation asset forth in claim 3, wherein the control has an input device arrangedand configured to select between the demand dependent mode and apriority mode in which a priority is manually set with respect to thefirst object or the second object.